---
name: "randseed"
section: "3tcl"
platform: "linux"
package: "tcllib"
version: "2.0+dfsg-4"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/randseed"
---

# randseed(3tcl)

Utilities for random channels

```

```

## NAME

tcl::randomseed - Utilities for random channels

## SYNOPSIS

package require **Tcl 8.5 9**

package require **TclOO**

package require **tcl::randomseed ?1.1?**

**::tcl::randomseed**

**::tcl::combine** *seed1* *seed2*

```

```

## DESCRIPTION

The **tcl::randomseed** package provides a a few utility commands to help with the seeding of **tcl::chan::random** channels.

## API

- **::tcl::randomseed**

  This command creates returns a list of seed integers suitable as seed argument for random channels. The numbers are derived from the process id, current time, and Tcl random number generator.

- **::tcl::combine** *seed1* *seed2*

  This command takes to seed lists and combines them into a single list by XORing them elementwise, modulo 256. If the lists are not of equial length the shorter of the two is padded with 0s before merging.

## BUGS, IDEAS, FEEDBACK

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category *virtchannel* of the *Tcllib Trackers* \[http://core.tcl.tk/tcllib/reportlist\]. Please also report any ideas for enhancements you may have for either package and/or documentation.

When proposing code changes, please provide *unified diffs*, i.e the output of **diff -u**.

Note further that *attachments* are strongly preferred over inlined patches. Attachments can be made by going to the **Edit** form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar.

## KEYWORDS

/dev/random, merge, random, reflected channel, seed, tip 219, virtual channel

## CATEGORY

Channels

## COPYRIGHT

```
Copyright (c) 2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>
```